Kanto Tauros: Probably bad outside of mixed Sheer Force sets (I doubt LO Blizzard OHKOs Tusk).
Kanto Articuno: Needs Tera to be viable. Tera Water + Freeze Dry is perfect coverage, Tera Electric + Ice Beam is very close to that. Add Roost and Sub/Hurricane and you have a decent Mon, but it really needs Tera.
Galar Articuno: Trolls Lando with Competitive. Tera allows to get rid of the crappy typing but it isn't as desperate as Kanto version.
Kanto Zapdos: God Mon. Lost Defog but not offensive potential. Checks lots of threats, like Tusk.
Galar Zapdos: Another God Mon that is only really checked by the Kanto version (pretty sure Gholdengo can be bypassed with Band Tera). Abuses Lando hard.
Kanto Moltres: Flame Body enjoyer, Tusk check, rain sweeper, etc. Lots of Tera potential.
Galar Moltres: Will sweep unprepared teams, one of the best Ghost checks out there.
Mewtwo: Uber.
Mew: Lost many moves, but still very annoying, especially as a suicide lead. Would ban it, but Smogon won't.
Alolan Muk: One of the best defensive Mons. Enjoys the absence of Gliscor, Restalk + Knock combined with Poison Touch will beat many teams.
Alolan Dugtrio: Actual Sand sweeper? Probably too frail for it.
Alolan Persian: Fur Coat + Tera allows this Mon to check what it wants. Needs Rest to stick around though.
Alolan Raichu: Pincurchin gains another friend!
Galar Slowbro: Oh, right, another HO Cheesmon. People will want the ability banned, I disagree, the more hax present in the meta, the better.
Galar Slowking: Was overrated last Gen, but Chilly Reception combined with the ability to change type makes it actually good.
Hisui Electrode: Overall bad, but Tera Ice might have some use to gain almost perfect coverage. Unlike other Mons, it has Grass Stab to not get walled by Gastro. Needs huge support though.
Hisui Arcanine: Kinda walled by Garchomp, but Rock Head STABs are fun with Band.
Johto Typhlosion: Charizard is a better Sun wallbreaker, but Typhlosion walls Charizard with Flash Fire and still throws Eruptions.
Hisui Typhlosion: No Blacephalon means this is going to be a decent Mon, it's faster than Skeledirge, so it's not outclassed.
Kyogre: Uber.
Groudon: Uber.
Rayquaza: Uber.
Uxie: Tera Poison or Electric will be hard to take down, but it struggles to diferenciate from Cresselia, except for Rocks, Memento and U-Turn.
Mesprit: Pure Psychic outclassed by everything.
Azelf: Suicide lead and fun Tera NP sweeper.
Dialga (both forms) : Uber.
Palkia (both forms) : Uber.
Heatran: Fuck this Mon, probably the Mon whose dominance across the Gens I hate the most. Tera gives him even more options but at least it lost Toxic. This Means that I can send Roost Roaring Mon and he has to use Dragon Pulse or Body Press to do something.
Giratina-A: Should start Uber for sure, but could be retested. Rest now has 8 PPs and every offensive Mon has coverage for it. It will still be hard to break and can even sweep with CM, but I don't think it will be impossible level to break and the 4 slot syndrome its present ( Rest is a must. Without Shadow Ball Gholdengo comes for free. Without either WoW or Roar, everything set ups on Giratina,but Defog and Sleep Talk are also wanted ). It's a cool Defogger that can hit Gholdengo with STAB Shadow Ball and at the same time be a spinblocker itself.
Giratina-O: Now, this is still an obvious Uber.
Cresselia: Tera and the exclusive moves give this Mon potential in a type of teams.
Arceus (all formes) : Uber. Yes, even Bug form. Especially Bug form.
Unovan Samurott: Bad and outclassed.
Hisui Samurott: Very good with the move that does damage and sets Spikes. Hatterene doesn't like this.
Tornadus-I: Tailwind goon, otherwise use T.
Tornadus-T: Lost lots of Mons, but still is an offensive Regenerator Mon, so will still be dominant.
Thundurus-I: Tera Ice + NP is the definition of high risk, high reward Mon.
Thundurus-T: This on the other hand is better with Tera Water to abuse Volt Absorb even better, having only weakness to Grass.
Landorus-I: It lost some moves, but don't commit the same mistake of giving him a chance, it's still an obvious Uber that now even has NP and the ability to change typing.
Landorus-T: Even without Toxic, Defog and Knock Off, this is still desthroning Tusk as the best Mon, it's versatile, powerful and bulky.
Meloetta: Tera will increase this Mon use, Relic Song is fun.
Zoroark-Hisui: No, this is not an excuse to retest Annihilape. Probably a decent Mon though, with a those immunities.
Braviary Hisui: Idk if this is better than Galar Articuno.
Lilligant Hisui: Due to Hustle, this Mon is broken and terrible at the same time. Will make ragequit many players who use it and face it.
Delphox: Can now get rid of the typing and be a decently powerful Mon that doesn't die to everything.
Chesnaught: Decent defensive Spiker that checks stuff. The less Knock Off users, the better for it. Probably bulky enough to survive to Wave Crashes from Band Adamant Tera Water Floatzel in Rain and even if not, Spiky Shield at least wears it down and stalls the Rain turns.
Carbink: Only useful in Nuzzlockes that don't allow Legendaries like Diancie, which is the same Mon, but better.
Diancie: Tornadus check that puts Rocks but has 4 move slot syndrome and no recovery outside of Rest. Not entirely bad, but hard to use. At least learns Trick Room...
Hoopa: Powerful Shadow Balls time. Can change typing to not die from the first random Knock Off.
Hoopa-U: It was already close to broken without Tera, but with it, I can't see this Mon staying.
Volcanion: The weather abusser and punisher, now can remove the Rocks weakness to either be even more powerful, or become Ground with just 2 weaknesses.
Hisui Avalugg: Why couldn't this be Ice Steel? Has worse Stats than Kalos version and since you gonna Tera it anyway, has almost no use.
Hisui Goodra: This is what a well made Duraludon should have been. High Stats, solid typing and good movepool. Won't dominate, but will be a useful wall (with AV or Restalk) or wallbreaker (Specs)
Alola Decidueye: Defogger not blocked by Gholdengo. Can change type to abuse Spirit Shackle better. Still slow and frail.
Hisui Decidueye: Stronger but still slow and frail. Scrappy and the move it has give it some potential.
Magearna: For me, only one move make this Mon an Uber: Trick. It still has Trick, so it's still broken with Specs, as every single what would be checks is crippled with Trick.
Rillaboom: Even with the huge movepool lose, this will be viable with Band Wood Hammer and his friend Magnezone.
Inteleon: Why would I use this ugly Mon when Greninja exists?
Zacian (both forms) : Due to the nerf his ability received, it's now much worse than it used to be and therefore can be retested... in Ubers.
Zamazenta (Hero) : I see this the most likely former Uber to come down. Pure Fight is a bad typing and it's not strong enough to break the Tier in my opinion. It is however useful vs other offensive teams, which is a good thing.
Zamazenta (Crown) : This is the least likely Mon to be balanced in OU due to godly typing and Stats, but can still be tested AFTER both Hero form and Giratina-A.
Eternatus: Uber.
Urshifu-S: Uber.
Urshifu-R: High chance of being Uber due to SD. This can change with Giratina-A and Zamazenta in the meta, however.
Zarude: Gained SD... Don't we have enough Grass Dark Mons in the meta, though? I include Wo-Chien in this list.
Regieleki: With Tera Ice this is a broken Mon, no way around that. But ok, allow it in OU for my beloved Iron Treads to finally shine.
Regidrago: Terablast allows it to destroy fairies. Still probably balanced though, it's not too fast.
Glastrier: Changing typing makes it better than it used to be, but the Speed will still limit it.
Spectrier: If it gained Moonblast, I would consider giving it a chance in OU. With the cancerous Draining Kiss (I would Dexit this move if I could), no way, go straight to Ubers.
Calyrex: Ugly and bad.
Calyrex when on a horse: Less ugly and broken.
Wyrdeer: Intimidate looks like the only thing going for it.
Kleavor: Very good Mon, mostly for Stone Axe putting Rocks and doing damage. Hatterene doesn't like this, again.
Ursaluna: Extremely powerful wallbreaker that will be very hard to use. Trick Room gains another abuser.
Basculegion: With Last Respects out of the way, this is still a very powerful Rain sweeper, both with Swift Swim and Adaptability.
Sneasler: Dire Claw looks fun... except for those facing it. Very good Mon.
Overqwil: Cute and strong. Has competition with Alolan Muk, but SD, Intimidate, hazards and bigger physical bulk differentiate it enough.
Enamorus (both forms) : Typing and Stats alone make them OU (unless both are viable, which would make them competr between them and bring usage down due to Species Clause).
Things I want to return:
-Houndstone
-Chien Pao (I know it's broken, but it's fun)
-Victini
-Meganium with some new toys.
-Centiskorch
-Weezing
-Primarina
-Tangrowth
-Ninetales and Sandslash
-Dhelmise
-Knock Off, but only to Weavile and Krookodile
-Roost, but only to Scizor
-Megas
Things that I don't want to return:
-Banned Mons outside of Houndstone and Chien Pao.
-Transferable moves.
-Every legendary not named Victini. Especially all the Alolan ones, fuck them all.
-Gliscor
-Clefable